Aluminum is defo out.
I'm curious as to this. Why is it Aluminium tanks are frowned upon? I have two so am wanting to know what it is I am not aware of before its too late :-/
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Aluminum is defo out.
Aluminum has a reputation in the boat industry of being installed quickly, cheaply and usually incorrectly. I personally had two failures due to water being trapped beneath them, and know of quite a few failures of aluminum tanks in my general boating area...some only 10 years old.
For FRP tanks, Epoxy lined is the way to go. Check with a few boat builders or suppliers who use Epoxy lined FRP tanks for diesel to insure right Epoxy is used. They are not all created equal.
Am I wrong to worry about steel?
Marin", what kind of composite tanks on GBs? Thank you all for the valuable input. Anything else you can think of would be appreciated!
I will have spring-loaded bronze ball valves at low point of tanks with plugs for added securityQUOTE]
ABYC 33.8.3 Tapered plug valves with an external spring shall not be used.
Thanks I didn't see that. But are we talking about "ball valves" here? Somebody in this thread linked me to McMaster-Carr to show me one. Are low point drains/valves not allowed? I thought they were...
Of all the systems I have purchased for this boat, this is by far the hardest decision....
I agree with Tom's remarks with one addition that I think is essential for long term integrity of steel tanks and that is a skookum fuel polishing system. Delfin has 7 tanks, and I will routinely do a 12 hour polish on a tank once it gets to 90% empty. This is best done underway, when things are sloshing around. After 5 years, I have yet to see a drop of water in the polishing filters, even though the pickups are directly at the bottom of the tanks. If you keep the water out, the tanks will last a very, very long time.Steve, here is my take:
Well designed steel tanks are perfectly fine provided you keep the water from pooling on the outside and can drain/empty the tanks completely. A 3 stage filter system ala Tony Athens will protect you from most dirty fuel issues and problems. Most important, fill up from a known source wherever possible.
On new tanks, no matter what material was used, a complete cleaning before the first fill is essential. Internal construction debris is all too common.
Late to this, but Nigel Calder has some good ideas on design and materials,see "Cruising Handbook" pp213-215. He does not like s/steel or aluminum tanks
Want to remember this for possible investigation.You could always coat the inside of steel tanks with aircraft fuel tank sealer when they're built. Epoxy or other coating on the outside.
Good advice also. I would have thought there would be more 'polly tank' replies/contributors?IF I were building a boat today I would select modest sized rotorcast polly fuel and water tanks .
Sure a proper Monel tank set would be better , but the life of polly seems to be unlimited (like the monel) so the downside is the slightly more complex installation.And the inability to have a more complex shape , like a sump directly under the fill port.
A polly tank grows after being 1st fueled , so the drill is to put it in place on its shelf , fill it with fuel and in 48 hours foam it in place , or secure it as you see fit.Then transfer the fuel to the next tank, and let it grow.
With about 40G small enough to not require internal baffels , a series of tanks would be required for long range capacity.
This would not be a problem as the 40G tank would feed about a 100G genuine monel DAY fuel tank. OR a deep but narrow polly day tank
The advantage is when the cruise is over the 40G tanks would be de-fueling by running it thru the noisemaker or heating plant or diesel range.
Eventually ONLY the snap to maintain day tank would hold fuel, so no bugs , no problems .
As said in the Graduate decades ago, Plastic is the future!
There is little rusting inside a steel tank , as even with water in the tank oxygen is also required.
A bottom drain solves the water in the fuel hassle cruedly.
A proper sump solves the water in the fuel problem to perfection.
I have a lot to consider. "Third Reef"...I did join boatdiesel.com and will look for that article, thanks. "FF", I considered poly, but heard strories of diesel smell permeating in and out of the poly.